Lid for a mug or tumbler



FIG. 1 is a top side perspective view of a lid for a mug or tumblershowing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a rear elevational view thereof; and,

FIG. 6 is a top plan view thereof.

The broken lines in the drawings are for illustrative purposes only andform no part of the claimed design.

The ornamental design for a lid for a mug or tumbler, as shown anddescribed.